In recent years, a calling party has made a call request through a computer terminal or the like. In this case, the computer terminal or the like transmits information specifying a telephone number of a call origination telephone terminal (that is a telephone terminal that is used by a calling party), and information specifying a telephone number of a call destination telephone terminal to a telephone relaying apparatus. Then, a telephone relaying apparatus makes a call to the call origination telephone terminal, and makes a call to the call destination telephone terminal. The call origination telephone terminal and the call destination telephone terminal perform a call process through the telephone relaying apparatus.
For example, a method of controlling a third party call is disclosed in a Request For Comment (RFC) 3725. According to this method, when a mobile terminal makes an instruction on a call destination to the telephone relaying apparatus through a data communication network, the telephone relaying apparatus makes a call to the call destination and the mobile terminal that made an instruction.
In addition, the fact that identification information of the telephone device that becomes the call origination and the telephone number of the call destination are stored in the telephone relaying apparatus in advance is disclosed in Patent Document 1. When receiving a telephone call from the telephone device, the telephone relaying apparatus establishes this telephone connection, reads out a telephone number corresponding to the identification information of the telephone terminal, makes a telephone call using this telephone number, and thereby performs the telephone relaying process.